If $9a + 9b = 5$ and $5x + 5y = 1$, what is $20y + 27b + 20x + 27a$ ?
Explanation: $= 27a + 27b + 20x + 20y$ $= (3) \cdot (9a + 9b) + (4) \cdot (5x + 5y)$ $= (3) \cdot (5) + (4) \cdot (1)$ $= 15 + 4$ $= 19$